Laparoscopic surgery which is also known as keyhole surgery or minimally invasive surgery (MIS) is a surgical technique in which operations in the abdomen are performed through small incisions provided in the abdomen wall. The incisions are typically of the order of 0.5-2.5 cm and provide the surgeon with access to the interior cavity for performing the necessary surgical operation. The cavity is typically inflated with carbon dioxide, to increase the volume of the cavity so as to provide the necessary working and viewing space for the surgeon.
The surgical instruments are inserted into the abdominal cavity through a cannula or trocar located within the incisions in the cavity wall. For laparoscopic surgery, each operation typically requires a minimum number of such incisions to enable the use of a sufficient number of instruments as determined by the surgeon. The control of the instruments is effected outside the body cavity. By using such minimally invasive surgical techniques as opposed to earlier open surgical procedures there are a number of advantages including the fact that the smaller incisions used amongst other factors reduces the pain of the operation and shortens recovery times for the patients. There are many factors contributing to reduced patient morbidities with minimally invasive surgery over open surgery which make this an increasingly attractive option for patient and surgeon. For this reason there is a more recent push towards even less invasive laparoscopic approaches. There are various names and acronyms attached to this emerging technique of surgery including Single Incision Laparoscopic surgery (SILS) and Lapro-Endoscopic Single-Site Surgery (LESS) amongst many others. Fundamentally, the aim is to operate from one site, typically at the umbilicus, thereby eliminating the extra ports and improving cosmesis for the patient. However, this approach introduces additional constraints on the operator over the traditional laparoscopic approach and is likely to require new flexible and accessible instruments to complete the surgical procedure efficiently.
As the surgery is completed through a relatively small number of small diameter access points to the interior cavity, it is preferable to have only one operator of the instrumentation within the cavity. However due to the number of instruments that may need to be operated concurrently, there is often a requirement for two or more persons to operate the instruments concurrently, which can be a nuisance in that each of the multiple persons add cost and potentially increases the risk of a complication occurring. The addition of extra personnel is a challenge for private practices that may not have the human resources to meet this need. Whether in a public or private hospital setting, the majority of surgeons would prefer to be in control of their set up and the operating environment.
Furthermore, the site of the surgery is often occluded by another organ that needs to be moved out of the field of view to allow access to the surgery site. In the context of traditional open surgery where access to the operating site is more open, this can be easily achieved by the surgeons hand or an assistants hand or a simple retraction device held in place by the operator's hand. This is often considered a conventional step in the operation. However with laparoscopic surgery, while the moving of occluding organs is still necessary, it is more difficult to achieve and has typically been achieved in one of two ways, both of which utilise retraction devices.
Known retraction devices work on the principle of holding up the target organ from outside the abdominal cavity. They are a mix of single patient use (SPU) and reusable devices depending on the manufacturer. Typically, a metal shaft is inserted via a 10/12 mm or 5 mm port and has various applicator end section designs depending on the manufacturer and model. These can for example be dimensioned to resemble finger type designs, or a simple wedge shape. Some of these designs are of metal construct but there are a number of inflatable types also available. These end applicator sections are designed and constructed in many different ways but essentially they all perform a similar function in lifting the target organ. This target organ will depend on the actual operation being completed but in the context of surgery in the area of the gastroesophageal junction and surrounding structures the left lobe of the liver is typically required to be lifted out of the field of view. They are advanced under the target organ, for example the liver, which is then leveraged up and out of the field of view using a rigid lever. The device is then held in position by an assistant or some devices are fixed to an external support frame which acts as an aid to fix it into position. In all arrangements the retraction device is secured from the outside and most designs require a dedicated port throughout usage.
Another common retraction method is applied to the right side of the liver. Typically this method is used to grasp, retract and orientate the gallbladder and the attached right liver lobe in to a position that provides a ‘critical view’ of the key structures at the root of the gallbladder. This procedure is known as the Laparoscopic Cholecystectomy. The typical set up for this procedure requires 4 ports, one of which is dedicated to the retraction of the gallbladder and right liver lobe.
The use of dedicated ports suffers in that an additional incision is required, and as will be appreciated from above, there is a desire in laparoscopic surgery to keep the number of incisions to a minimum. There is also a cost disadvantage of having to employ an additional port. Furthermore the maintaining of the retraction device in situ using a person requires that person to maintain a static hold for the entire procedure or certainly over prolonged periods of time causing fatigue. Fatigue usually leads to movement and in most cases there is a lack of operator control from the outset as they are relying on an assistant. Other device types require the assembly of an external fixation scaffolding around the operating table so as they can be fixed to it for the duration of the procedure and this can occupy valuable space and hinder the surgeon in his performance of the surgery. They are also reusable and require sterilisation and maintenance.
Therefore there are a number of problems associated with existing retraction devices and their methods of use. There is also a distinct shortage of solutions to deal with emerging techniques such as the single incision surgery and all of its associated procedures including but not limited to Laparoscopic Cholecystectomy, Laparoscopic Gastric Banding and Bypass, and Laparoscopic Nissen Fundoplication. Traditional laparoscopic approaches also offer challenging retraction in operations such as, but not restricted to, laparoscopic colon procedures. During this procedure the small bowel typically has to be maintained/retracted in a position out of the field of view of the target large bowel or colon. Therefore both approaches, namely, traditional laparoscopic and single incision surgeries, offer many retraction difficulties for the operator/surgeon. The emergence of the single incision approach leads to increased difficulties as there are even more limiting factors due the position of the single incision and the operating difficulties this presents to the surgeon.